extern int SquareDistance[SQUARE_NB][SQUARE_NB];
-extern Bitboard RookMasks [SQUARE_NB];
-extern Bitboard RookMagics [SQUARE_NB];
-extern Bitboard* RookAttacks[SQUARE_NB];
-extern unsigned RookShifts [SQUARE_NB];
-
-extern Bitboard BishopMasks [SQUARE_NB];
-extern Bitboard BishopMagics [SQUARE_NB];
-extern Bitboard* BishopAttacks[SQUARE_NB];
-extern unsigned BishopShifts [SQUARE_NB];
-
extern Bitboard SquareBB[SQUARE_NB];
extern Bitboard FileBB[FILE_NB];
extern Bitboard RankBB[RANK_NB];
}
-/// shift_bb() moves a bitboard one step along direction Delta. Mainly for pawns
+/// shift() moves a bitboard one step along direction D. Mainly for pawns
-template<Square Delta>
-inline Bitboard shift_bb(Bitboard b) {
- return Delta == DELTA_N ? b << 8 : Delta == DELTA_S ? b >> 8
- : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
- : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
+template<Square D>
+inline Bitboard shift(Bitboard b) {
+ return D == NORTH ? b << 8 : D == SOUTH ? b >> 8
+ : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == SOUTH_EAST ? (b & ~FileHBB) >> 7
+ : D == NORTH_WEST ? (b & ~FileABB) << 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9
: 0;
}
template<PieceType Pt>
inline unsigned magic_index(Square s, Bitboard occupied) {
+ extern Bitboard RookMasks[SQUARE_NB];
+ extern Bitboard RookMagics[SQUARE_NB];
+ extern unsigned RookShifts[SQUARE_NB];
+ extern Bitboard BishopMasks[SQUARE_NB];
+ extern Bitboard BishopMagics[SQUARE_NB];
+ extern unsigned BishopShifts[SQUARE_NB];
+
Bitboard* const Masks = Pt == ROOK ? RookMasks : BishopMasks;
Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics;
unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts;
template<PieceType Pt>
inline Bitboard attacks_bb(Square s, Bitboard occupied) {
+
+ extern Bitboard* RookAttacks[SQUARE_NB];
+ extern Bitboard* BishopAttacks[SQUARE_NB];
+
return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
}
}
+/// popcount() counts the number of non-zero bits in a bitboard
+
+inline int popcount(Bitboard b) {
+
+#ifndef USE_POPCNT
+
+ extern uint8_t PopCnt16[1 << 16];
+ union { Bitboard bb; uint16_t u[4]; } v = { b };
+ return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];
+
+#elif defined(_MSC_VER) || defined(__INTEL_COMPILER)
+
+ return (int)_mm_popcnt_u64(b);
+
+#else // Assumed gcc or compatible compiler
+
+ return __builtin_popcountll(b);
+
+#endif
+}
+
+
/// lsb() and msb() return the least/most significant bit in a non-zero bitboard
#if defined(__GNUC__)
inline Square msb(Bitboard b) {
assert(b);
- return Square(63 - __builtin_clzll(b));
+ return Square(63 ^ __builtin_clzll(b));
}
#elif defined(_WIN64) && defined(_MSC_VER)